The invention relates to a device for fixing a band-shaped or strip-shaped edge material to a narrow side of a panel-shaped workpiece, wherein the device has a feed mechanism for supplying the edge material along a feed path to the narrow side of the workpiece, and also at least one infrared emitter for activating an adhesive layer, facing the workpiece, of the edge material, and a pressing mechanism for pressing the edge material onto the narrow side of the workpiece.
Devices for fixing a band-shaped or strip-shaped edge material are used for example in edge-processing machines. In such machines, a panel-shaped workpiece, in particular a wooden workpiece, is moved continuously in a transport plane, and with the aid of a fixing device of the above-mentioned type a band-shaped or strip-shaped edge material, which is frequently also referred to as an “edge veneer”, can be supplied to a narrow side of the workpiece which is oriented parallel to the direction of transport of the workpiece. The edge material has an activatable adhesive layer on its side facing the workpiece. During the supplying of the edge material to the narrow side of the workpiece, the adhesive layer is activated, and then the edge material is pressed against the narrow side of the workpiece and is thereby fixed to the narrow side. In many cases, the workpiece is then, together with the edge material fixed to the narrow side, sent for subsequent processing, in which regions of the edge material projecting over the workpiece in the direction of transport are separated off from the workpiece.
Many different configurations of devices for fixing an edge material to a narrow side of a panel-shaped workpiece are known. Frequently, a heat-activatable hot-melt adhesive is used as the adhesive layer of the edge material. The hot-melt adhesive may be activated for example with the aid of hot air under pressure or alternatively with the aid of plasma irradiation. Such devices are known to the person skilled in the art for example from WO 2012/130224 A1 and DE 20 2009 009 253 U1. It has also already been proposed to use an edge material which consists of two preferably coextruded plastics-material layers of different hardnesses. One of the plastics-material layers forms an adhesive layer which can be activated by exposing it to laser radiation in order to bond the edge material to the workpiece. Such plastics materials are known for example from EP 1 163 864 B1 and EP 1 852 242 B1.
The activation of the adhesive layer of the edge material with the aid of a laser beam is also known from DE 10 2006 056 010 B4. However, it necessitates a laser source which is cost-intensive and of complex design, and requires a not inconsiderable lead time before the device can actually be used for fixing the edge material.
A considerable lead time is also necessary in order to activate the adhesive layer of the edge material with the aid of hot air under pressure or in general with the aid of a hot gas under pressure. Furthermore, this procedure too involves not inconsiderable costs.
The equivalent also applies to the activation of the adhesive layer with the aid of plasma irradiation. The plasma irradiation requires not inconsiderable expense in terms of apparatus and likewise involves a considerable lead time before the adhesive layer of the edge material can actually be activated.
It has also already been proposed to use an infrared emitter to activate the adhesive layer, for example in DE 20 2006 020 669 U1 or alternatively in DE 20 2009 009 253 U1. Infrared emitters are known per se to the person skilled in the art for heating purposes. When irradiating the edge material with infrared radiation, there is however the difficulty that merely the adhesive layer on the rear side of the edge material is to be activated by means of the infrared radiation, but the visible face of the edge material should not be adversely affected by the infrared radiation.
It is therefore an object of the present invention to develop a device of the generic type such that the adhesive layer of the edge material can be activated with the aid of infrared radiation using a reliable process without adversely affecting the visible face of the edge material.